Steel reinforcing bars (“rebar”) are used in reinforced concrete in building structures. During the construction of buildings, the ends of the rebar are often exposed and extend upwardly from recently poured concrete sections or walls. Exposed ends are sharp and present a hazard to workmen, particularly to workmen working overhead. Many workmen have sustained puncture injuries, and in a significant number of cases have been killed, due to accidentally falling or stepping onto the exposed ends of the rebar.
Various protective safety covers have been proposed and used to protect workmen from this hazard. Bush U.S. Pat. No. 4,202,378 and Bush Design Pat. No. 262,093 refer to a protective safety cover for use on the free projecting ends of rebar comprising a hollow cylindrical body of a deformable plastic material, the body being closed at one end and open at the other. A plurality of inwardly extending projections are formed within the open end of the cylindrical body to secure the protective cover to the rebar. The closed end of the body has a flat circular head which extends radially outwardly from the body to present an enlarged flat impact surface. Other plastic protective covers for rebar are discussed in Schimmelpfenning U.S. Pat. No. 5,884,443 and Don De Cristo Concrete Accessories Inc. Catalog “Plastic Rebar Guard”, p. 43. Lunn U.S. Pat. No. 4,833,850 proposed a protective cover for rebar in the form of a metal support adapted to hold a impact absorbing spherical cushion.
When it was realized that these all plastic protective covers were subject to penetration upon severe impact, such as a workman falling from a height, it was proposed to insert a separate piece of rebar through lateral holes near the closed end of the cylindrical body to provide for a steel stop as discussed in WO91/14839 and Underwood U.S. Pat. No. 5,363,618. This approach is not self-contained, is inconvenient, and subject to not being consistently practiced.
Consequently, protective covers having a built in metal plate or “seat” in the bottom of the closed end of the body were developed. Protective covers of this type are discussed in Schnepf U.S. Pat. No. 5,313,757, Workman U.S. Pat. Nos. 5,447,290 and 5,613,336, Deslauriers Impalement Protective “Safety Cap DISC System”, Buffalo American Allsafe Company “BarGard”, Mutual Industries Inc. OSHA Rebar Cups Part Numbers 14640-4 and 14640-5, Dunn U.S. Design Pat. No. 408,268, and Kassardjian et al U.S. Pat. Nos. 5,381,636, 5,523,043, 5,568,708, 5,824,253, 5,943,836, 5,946,871 and Design No. 363,657. Protective covers with metal plates or seats passed the original Cal OSHA drop test.
However, after an investigation of job site injuries, Cal OSHA subsequently declared that the existing protective covers with metal plate or seat were inadequate, primarily due to being subject to penetration through the side of the cylindrical body upon impact on the head, resulting in serious puncture injuries to workmen falling onto the rebar.
Cal OSHA since established a new and more stringent drop test which all new rebar protective covers are required to meet. Kassardjian et al U.S. Pat. No. 5,729,941 relates to a rebar cover having a preformed metal stamping in the form of a bowl-shaped metal seat which is incorporated in the closed inner end of the cylindrical body. The bowl-shaped metal seat is said to be of a composition and thickness to prevent penetration of the rebar through the seat and thereby preclude penetration of the rebar through the side of the cover body upon impact.
The use of a preformed bowl-shaped metal stamping as the seat adds to the expense of the rebar protective cover.
Subsequently, a rebar protective cover having a hollow cylindrical body and impact head of a thickness and integrally formed of a plastic material was developed which was found to provide a protective cover which passes the current Cal OSHA drop test. This rebar protective cover is disclosed in applicant's co-pending U.S. patent application Ser. No. 09/569,826, filed May 12, 2000, the disclosure of which is incorporated herein by reference.